Hey doug,
In your case, you're using a starter which somewhat negates the need for a perfect yeast propagation environment. You also are not doing full boils so your top up water is already bringing O2 back into the batch.

Correct! But the thread starter appears to be doing the same. I thought my experiences were relative to his.

Like I said above, since I started using my aeration kit, my attenuation on average has gone up by about 10%. My beers have gotten better as a direct result---.

Better is a very individual concept. If your attenuation goes up then your alcohol content goes up and your beer is dryer. That is ok if the style of beer matches the dryness that you get. But if you are not brewing a dry style then you may go too far with your attenuation.

I do not really like dry beer. I tend to like Porters and stouts and brown ales that have a little residual sweetness. I have brewed some dryer beers and never had a problem with attenuation. I usually always reach my goals within a small margin of error.

I can see why someone who can never reach final gravity goals would want to try this to get their attenuation up and gravity down.

Better is also relative to what you are shooting for. As long as my beer attenuates in the neighborhood of what I am shooting for, it's all good and as long as I can do it consistently I am happy. My strainer works great for me. If one desires to tweak and push the limits of the yeast attenuation that is a personal preference as well.

This is a good discussion in general because it helps to know that if you want to tweak your recipe and get a drier beer, then possibly aeration is a variable to mess with.

I'm actually thinking about trying an experiment to remove any bias. The only problem is, I don't have two similar small 1gal fermenters. Once I get some, I'm going to boil up 2 gallons of 1.050 wort and split it. I'll pitch equal amounts of dry yeast then shake the heck out of one and inject pure O2 in the other. Then I'll do a time lapse video of both and test the gravity at certain intervals. Hopefully the results will put this debate to rest at least temporarily.

What do you guys think?

I like the idea of an experiment, but what exactly are we trying to prove? That O2 injected beer ferments "better", faster, or more complete than sloshed and frothed or that the beer that has been injected tastes "better", closer to style, or is a more refined end product?

Well, I'm not sure everyone here is convinced of the actual difference in end result between the methods ranging from doing nothing, to sloshing, to oxygenating. That's what I'd like to test.

Getting O2 back up to near saturation is just one way to increase consistency in my opinion. Other methods are adding O2 back in for sure, but I bet the levels are all over the map so you'll get different results. Some people are fine with variation and just fly by the seat of their pants on every batch, but I like to play beer god and control as much as I can.

As others mentioned, it seems a lot easier to tweak end results by adding/reducing fermentables or choosing yeast strains with known higher/lower attenuation rather than try to control the environment perfectly to alter their inherent tendencies.

Better is a very individual concept. If your attenuation goes up then your alcohol content goes up and your beer is dryer. That is ok if the style of beer matches the dryness that you get. But if you are not brewing a dry style then you may go too far with your attenuation.

MORE is not always better.

To each his own, of course---I'm not trying to set any hard and fast "rules" here.

If I'm not brewing a dry style, then I'll just include unfermentable sugars (such as maltodextrine) in my grain bill. As I said elsewhere, your grain bill (and, specifically, your ratio of fermentable to unfermentable sugars) is much easier to control than the performance of your yeast. As such, unless I'm brewing all sweet beers (which I don't), it seems that the easiest thing to do (especially in terms of consistency from batch to batch, which is important to me) is to achieve the highest possible attenuation (within reason), and then adjust the grain bill from batch to batch to achieve the style I want.

But like I said, to each his own. If you would rather try to control the yeast performance rather than the grain bill, more power to you.

I agree with you, but my point is that I started brewing before the technology of oxygenation existed for the homebrewer. I have spent years adjusting recipies to get them to taste the way I wanted them to based on my techniques.

I agree that perfecting oxygen saturation and adjusting the grain bill to alter the fermentable-to-nonfermentable sugar ratios is the correct thing to do if you are starting out in this hobby.

What I am unclear of is the difference it will make in the end. Maybe I save a little money on ingredients.....maybe I spend more because I have to add more unfermentables. Maybe the attenuation difference is alot....maybe not. I guess I agree with the idea of testing to see. Will I change my technique....probably not.

I ferment in buckets and I pour the work between my fermentation bucket and my bottling bucket about 10 times before I pitch my yeast. I get lot of pretty foam on the top and my fermentations start nicely. I think that is seems to work OK. I would use an aquarium pump aeration system if I had one though, less lifting/possible spilling of the wort.

I wouldn't suggest this is bad or wrong, but the column of air between your buckets isn't exactly sanitary. We're always paranoid about wild yeast "settling" down on our open buckets/chilled wort and your method is definitely increasing your risk. You might get through 20 batches before you get an off flavor, but I'm all about minimizing risk.